The following background discussion includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Delayed coking is a well known thermal cracking process used in various refineries that converts a residual feed into solid carbonaceous material (e.g., petroleum coke). The use of multiple drums in coking systems allows the coke drums to operate continuously. Generally, while one drum in a multiple drum system is being filled with a feed stream, another is being stripped, cooled, decoked, pressure checked, or warmed up (See e.g., http://www.coking.com/DECOKTUT.pdf and http://www.coking.com/SeminarUSA/Presentati onPDFs2012/FLUOR_BMilletKirkpatrick_FreshLookAt3DrumCokers_CokingCom_Galv_2012.pdf.).
Coking systems can sometimes be modified by adding a coke drum, replacing a coke drum, or shortening or expanding cycle times (e.g., step cycle (e.g., warm up time, drain time, etc.), drum cycle, system cycle, etc.). As used herein, a “step cycle” or “step cycle time” is the amount of time it takes one drum to complete a step (e.g., warm up, stripping, filling, etc.) in the delayed coking process. A “drum cycle time” or “drum cycle” is the amount of time it takes a single drum to complete all steps in the delayed coking process, from warming up to decoking. A “system cycle” or “system cycle time” is the amount of time it takes for all drums in the delayed coking process to complete a drum cycle. Each of the cycles can be altered (e.g., shortened or expanded). Some examples of modifying coking systems are described in “Fine-tune your delayed coker: obstacles and objectives” by J. D. Elliot (September 2004), found at http://www.fwc.com/publications/tech_papers/files/Fine%20tune%20your%20delayed%20coker.pdf.
While the above cited reference describes some possible modifications to existing coking systems, and some considerations in implementing a modification, it fails to provide either a system for analyzing effects of potential or actual modifications, or operating recommendations based on the analysis. Thus, there is still, a need for improved systems for analyzing an effect of modifying a coking system, and providing recommendations.